Use error constants whenever possible

Signed-off-by: Yilun <[email protected]>

client.go

@@ -8,7 +8,6 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"errors"
-	"fmt"
 	"log"
 	"net/url"
 	"strings"
@@ -193,14 +192,14 @@ func (c *Client) getOrComputeSharedKey(remotePublicKey []byte) (*[sharedKeySize]
 	}
 
 	if len(remotePublicKey) != ed25519.PublicKeySize {
-		return nil, fmt.Errorf("public key length is %d, expecting %d", len(remotePublicKey), ed25519.PublicKeySize)
+		return nil, ErrInvalidPubkeySize
 	}
 
 	var pk [ed25519.PublicKeySize]byte
 	copy(pk[:], remotePublicKey)
 	curve25519PublicKey, ok := ed25519.PublicKeyToCurve25519PublicKey(&pk)
 	if !ok {
-		return nil, fmt.Errorf("converting public key %x to curve25519 public key failed", remotePublicKey)
+		return nil, ErrInvalidPubkey
 	}
 
 	sharedKey = new([sharedKeySize]byte)
@@ -373,7 +372,10 @@ func (c *Client) handleMessage(msgType int, data []byte) error {
 			} else if action == setClientAction {
 				c.Close()
 			}
-			return errors.New(common.ErrMessage[errCode])
+			return errorWithCode{
+				err:  errors.New(common.ErrMessage[errCode]),
+				code: int32(errCode),
+			}
 		}
 		switch action {
 		case setClientAction:
@@ -623,7 +625,7 @@ func (c *Client) connect(maxRetries int) error {
 		return nil
 	}
 
-	return errors.New("max retry reached, connect failed")
+	return ErrConnectFailed
 }
 
 func (c *Client) reconnect() {
@@ -742,7 +744,7 @@ func (c *Client) SendText(dests *StringArray, data string, config *MessageConfig
 
 func (c *Client) processDest(dest string) (string, error) {
 	if len(dest) == 0 {
-		return "", errors.New("destination is empty")
+		return "", ErrNoDestination
 	}
 	addr := strings.Split(dest, ".")
 	if len(addr[len(addr)-1]) < 2*ed25519.PublicKeySize {
@@ -751,7 +753,7 @@ func (c *Client) processDest(dest string) (string, error) {
 			return "", err
 		}
 		if len(reg.Registrant) == 0 {
-			return "", fmt.Errorf("%s is neither a valid public key nor a registered nam", addr[len(addr)-1])
+			return "", ErrInvalidPubkeyOrName
 		}
 		addr[len(addr)-1] = reg.Registrant
 	}
@@ -769,7 +771,7 @@ func (c *Client) processDests(dests []string) ([]string, error) {
 		processedDests = append(processedDests, processedDest)
 	}
 	if len(processedDests) == 0 {
-		return nil, errors.New("all destinations are invalid")
+		return nil, ErrInvalidDestination
 	}
 	return processedDests, nil
 }
@@ -921,7 +923,7 @@ func (c *Client) sendTimeout(dests []string, payload *payloads.Payload, encrypte
 		for i := range plds {
 			size = len(plds[i]) + len(dests[i]) + ed25519.SignatureSize
 			if size > maxClientMessageSize {
-				return fmt.Errorf("encoded message is greater than %v bytes", maxClientMessageSize)
+				return ErrMessageOversize
 			}
 			if totalSize+size > maxClientMessageSize {
 				outboundMsg, err := c.newOutboundMessage(destList, pldList, encrypted, maxHoldingSeconds)
@@ -943,7 +945,7 @@ func (c *Client) sendTimeout(dests []string, payload *payloads.Payload, encrypte
 			size += len(dests[i]) + ed25519.SignatureSize
 		}
 		if size > maxClientMessageSize {
-			return fmt.Errorf("encoded message is greater than %v bytes", maxClientMessageSize)
+			return ErrMessageOversize
 		}
 		destList = dests
 		pldList = plds
@@ -1052,7 +1054,7 @@ func (c *Client) SetWriteDeadline(deadline time.Time) error {
 	c.lock.Lock()
 	defer c.lock.Unlock()
 	if c.conn == nil {
-		return errors.New("nil websocket connection")
+		return ErrNilWebsocketConn
 	}
 	return c.conn.SetWriteDeadline(deadline)
 }

error.go

@@ -1,7 +1,11 @@
 package nkn
 
 import (
+	"errors"
+	"fmt"
+
 	ncp "github.com/nknorg/ncp-go"
+	"github.com/nknorg/nkn/vault"
 )
 
 // ErrorWithCode is an error interface that implements error and Code()
@@ -23,8 +27,30 @@ func (e errorWithCode) Code() int32 {
 	return e.code
 }
 
+// Error definitions.
 var (
-	ErrClosed             = ncp.NewGenericError("use of closed network connection", true, true) // The error message is meant to be identical to error returned by net package.
-	ErrKeyNotInMap        = ncp.NewGenericError("key not in map", false, false)                 // for gomobile
-	ErrInvalidPayloadType = ncp.NewGenericError("invalid payload type", false, false)
+	ErrClosed               = ncp.NewGenericError("use of closed network connection", true, true) // The error message is meant to be identical to error returned by net package.
+	ErrKeyNotInMap          = errors.New("key not in map")                                        // for gomobile
+	ErrInvalidPayloadType   = errors.New("invalid payload type")
+	ErrConnectFailed        = errors.New("connect failed")
+	ErrNoDestination        = errors.New("no destination")
+	ErrInvalidDestination   = errors.New("invalid destination")
+	ErrInvalidPubkeyOrName  = errors.New("invalid public key or name")
+	ErrInvalidPubkeySize    = errors.New("invalid public key size")
+	ErrInvalidPubkey        = errors.New("invalid public key")
+	ErrMessageOversize      = fmt.Errorf("encoded message is greater than %v bytes", maxClientMessageSize)
+	ErrNilWebsocketConn     = errors.New("nil websocket connection")
+	ErrDecryptFailed        = errors.New("decrypt message failed")
+	ErrAddrNotAllowed       = errors.New("address not allowed")
+	ErrCreateClientFailed   = errors.New("failed to create client")
+	ErrNilClient            = errors.New("client is nil")
+	ErrNotNanoPay           = errors.New("not nano pay transaction")
+	ErrWrongRecipient       = errors.New("wrong nano pay recipient")
+	ErrNanoPayClosed        = errors.New("use of closed nano pay claimer")
+	ErrInsufficientBalance  = errors.New("insufficient balance")
+	ErrInvalidAmount        = errors.New("invalid amount")
+	ErrExpiredNanoPay       = errors.New("nanopay expired")
+	ErrExpiredNanoPayTxn    = errors.New("nanopay transaction expired")
+	ErrWrongPassword        = errors.New("wrong password")
+	ErrInvalidWalletVersion = fmt.Errorf("invalid wallet version, should be between %v and %v", vault.MinCompatibleWalletVersion, vault.MaxCompatibleWalletVersion)
 )

message.go

@@ -2,7 +2,6 @@ package nkn
 
 import (
 	"crypto/rand"
-	"errors"
 
 	"github.com/gogo/protobuf/proto"
 	"github.com/nknorg/nkn-sdk-go/payloads"
@@ -64,34 +63,34 @@ func decrypt(message []byte, nonce [nonceSize]byte, sharedKey *[sharedKeySize]by
 	decrypted := make([]byte, len(message)-box.Overhead)
 	_, ok := box.OpenAfterPrecomputation(decrypted[:0], message, &nonce, sharedKey)
 	if !ok {
-		return nil, errors.New("decrypt message failed")
+		return nil, ErrDecryptFailed
 	}
 
 	return decrypted, nil
 }
 
-func newBinaryPayload(data, messageId, replyToId []byte, noReply bool) (*payloads.Payload, error) {
-	if len(messageId) == 0 && len(replyToId) == 0 {
+func newBinaryPayload(data, messageID, replyToID []byte, noReply bool) (*payloads.Payload, error) {
+	if len(messageID) == 0 && len(replyToID) == 0 {
 		var err error
-		messageId, err = RandomBytes(MessageIDSize)
+		messageID, err = RandomBytes(MessageIDSize)
 		if err != nil {
 			return nil, err
 		}
 	}
 
 	return &payloads.Payload{
 		Type:      payloads.BINARY,
-		MessageId: messageId,
+		MessageId: messageID,
 		Data:      data,
-		ReplyToId: replyToId,
+		ReplyToId: replyToID,
 		NoReply:   noReply,
 	}, nil
 }
 
-func newTextPayload(text string, messageId, replyToId []byte, noReply bool) (*payloads.Payload, error) {
-	if len(messageId) == 0 && len(replyToId) == 0 {
+func newTextPayload(text string, messageID, replyToID []byte, noReply bool) (*payloads.Payload, error) {
+	if len(messageID) == 0 && len(replyToID) == 0 {
 		var err error
-		messageId, err = RandomBytes(MessageIDSize)
+		messageID, err = RandomBytes(MessageIDSize)
 		if err != nil {
 			return nil, err
 		}
@@ -104,39 +103,39 @@ func newTextPayload(text string, messageId, replyToId []byte, noReply bool) (*pa
 
 	return &payloads.Payload{
 		Type:      payloads.TEXT,
-		MessageId: messageId,
+		MessageId: messageID,
 		Data:      data,
-		ReplyToId: replyToId,
+		ReplyToId: replyToID,
 		NoReply:   noReply,
 	}, nil
 }
 
-func newAckPayload(replyToId []byte) (*payloads.Payload, error) {
+func newAckPayload(replyToID []byte) (*payloads.Payload, error) {
 	return &payloads.Payload{
 		Type:      payloads.ACK,
-		ReplyToId: replyToId,
+		ReplyToId: replyToID,
 	}, nil
 }
 
-func newMessagePayload(data interface{}, messageId []byte, noReply bool) (*payloads.Payload, error) {
+func newMessagePayload(data interface{}, messageID []byte, noReply bool) (*payloads.Payload, error) {
 	switch v := data.(type) {
 	case []byte:
-		return newBinaryPayload(v, messageId, nil, noReply)
+		return newBinaryPayload(v, messageID, nil, noReply)
 	case string:
-		return newTextPayload(v, messageId, nil, noReply)
+		return newTextPayload(v, messageID, nil, noReply)
 	default:
 		return nil, ErrInvalidPayloadType
 	}
 }
 
-func newReplyPayload(data interface{}, replyToId []byte) (*payloads.Payload, error) {
+func newReplyPayload(data interface{}, replyToID []byte) (*payloads.Payload, error) {
 	switch v := data.(type) {
 	case []byte:
-		return newBinaryPayload(v, nil, replyToId, false)
+		return newBinaryPayload(v, nil, replyToID, false)
 	case string:
-		return newTextPayload(v, nil, replyToId, false)
+		return newTextPayload(v, nil, replyToID, false)
 	case nil:
-		return newAckPayload(replyToId)
+		return newAckPayload(replyToID)
 	default:
 		return nil, ErrInvalidPayloadType
 	}

multiclient.go

@@ -2,8 +2,6 @@ package nkn
 
 import (
 	"context"
-	"errors"
-	"fmt"
 	"log"
 	"net"
 	"regexp"
@@ -13,6 +11,7 @@ import (
 	"sync"
 	"time"
 
+	multierror "github.com/hashicorp/go-multierror"
 	ncp "github.com/nknorg/ncp-go"
 	"github.com/nknorg/nkn-sdk-go/payloads"
 	"github.com/nknorg/nkn/util/address"
@@ -37,7 +36,6 @@ const (
 
 var (
 	multiClientIdentifierRe = regexp.MustCompile(MultiClientIdentifierRe)
-	errAddrNotAllowed       = errors.New("address not allowed")
 )
 
 // MultiClient sends and receives data using multiple NKN clients concurrently
@@ -142,7 +140,7 @@ func NewMultiClient(account *Account, baseIdentifier string, numSubClients int,
 						}
 						err := m.handleSessionMsg(addIdentifier("", i-offset), msg.Src, msg.MessageID, msg.Data)
 						if err != nil {
-							if err != ncp.ErrSessionClosed && err != errAddrNotAllowed {
+							if err != ncp.ErrSessionClosed && err != ErrAddrNotAllowed {
 								log.Println(err)
 							}
 							continue
@@ -192,7 +190,7 @@ func NewMultiClient(account *Account, baseIdentifier string, numSubClients int,
 	case <-success:
 		return m, nil
 	case <-fail:
-		return nil, errors.New("failed to create any client")
+		return nil, ErrCreateClientFailed
 	}
 }
 
@@ -245,7 +243,7 @@ func (m *MultiClient) GetDefaultClient() *Client {
 func (m *MultiClient) SendWithClient(clientID int, dests *StringArray, data interface{}, config *MessageConfig) (*OnMessage, error) {
 	client := m.GetClient(clientID)
 	if client == nil {
-		return nil, fmt.Errorf("client %d is not created or not ready", clientID)
+		return nil, ErrNilClient
 	}
 
 	config, err := MergeMessageConfig(m.config.MessageConfig, config)
@@ -285,7 +283,7 @@ func (m *MultiClient) SendTextWithClient(clientID int, dests *StringArray, data
 func (m *MultiClient) sendWithClient(clientID int, dests []string, payload *payloads.Payload, encrypted bool, maxHoldingSeconds int32) error {
 	client := m.GetClient(clientID)
 	if client == nil {
-		return fmt.Errorf("client %d is not created or not ready", clientID)
+		return ErrNilClient
 	}
 	return client.send(addMultiClientPrefix(dests, clientID), payload, encrypted, maxHoldingSeconds)
 }
@@ -305,7 +303,7 @@ func (m *MultiClient) Send(dests *StringArray, data interface{}, config *Message
 	}
 
 	var lock sync.Mutex
-	var errMsg []string
+	var errs error
 	var onRawReply *OnMessage
 	onReply := NewOnMessage(1, nil)
 	clients := m.GetClients()
@@ -333,7 +331,7 @@ func (m *MultiClient) Send(dests *StringArray, data interface{}, config *Message
 				sent++
 			} else {
 				lock.Lock()
-				errMsg = append(errMsg, err.Error())
+				errs = multierror.Append(errs, err)
 				lock.Unlock()
 			}
 		}
@@ -355,7 +353,7 @@ func (m *MultiClient) Send(dests *StringArray, data interface{}, config *Message
 	case <-success:
 		return onReply, nil
 	case <-fail:
-		return nil, errors.New(strings.Join(errMsg, "; "))
+		return nil, errs
 	}
 }
 
@@ -373,7 +371,7 @@ func (m *MultiClient) SendText(dests *StringArray, data string, config *MessageC
 
 func (m *MultiClient) send(dests []string, payload *payloads.Payload, encrypted bool, maxHoldingSeconds int32) error {
 	var lock sync.Mutex
-	var errMsg []string
+	var errs error
 	success := make(chan struct{}, 1)
 	fail := make(chan struct{}, 1)
 	go func() {
@@ -388,7 +386,7 @@ func (m *MultiClient) send(dests []string, payload *payloads.Payload, encrypted
 				sent++
 			} else {
 				lock.Lock()
-				errMsg = append(errMsg, err.Error())
+				errs = multierror.Append(errs, err)
 				lock.Unlock()
 			}
 		}
@@ -404,7 +402,7 @@ func (m *MultiClient) send(dests []string, payload *payloads.Payload, encrypted
 	case <-success:
 		return nil
 	case <-fail:
-		return errors.New(strings.Join(errMsg, "; "))
+		return errs
 	}
 }
 
@@ -470,7 +468,7 @@ func (m *MultiClient) handleSessionMsg(localClientID, src string, sessionID, dat
 	if !ok {
 		if !m.shouldAcceptAddr(remoteAddr) {
 			m.sessionLock.Unlock()
-			return errAddrNotAllowed
+			return ErrAddrNotAllowed
 		}
 
 		session, err = m.newSession(remoteAddr, sessionID, m.config.SessionConfig)